Title: The effect of pulsed electric fields on the rheology and microstructure of chitosan-poly(vinyl alcohol) composites

Authors: Stephen G. Giteru; Indrawati Oey; M. Azam Ali

Addresses: Department of Food Science, University of Otago, Dunedin, 9054, New Zealand; Centre for Bioengineering and Nanomedicine, University of Otago, Dunedin, 9054, New Zealand; Riddet Institute, Palmerston North, 4474, New Zealand ' Department of Food Science, University of Otago, Dunedin, 9054, New Zealand; Riddet Institute, Palmerston North, 4474, New Zealand ' Centre for Bioengineering and Nanomedicine, University of Otago, Dunedin, 9054, New Zealand; Department of Food Science, University of Otago, Dunedin, 9054, New Zealand

Abstract: Colloidal matrices of chitosan (CS) and poly(vinyl alcohol) (PVOH), 0.18 weight fraction CS (w_iCS), were subjected to pulsed electric fields (PEF) at specific energy 95 - 465 kJ/kg. The influence of pH was examined at various pHs 4.1, 4.8 (control), 5.2, 5.6 and 6.1. The treated samples were subsequently analysed for particle size and size distributions, surface zeta potential and viscoelastic behaviour. PEF at specific energy ≥275 kJ/kg resulted in larger particles and a wider range of particle size distribution (PSD). The zeta potential decreased with increasing pH, which corresponded with an increase in particle size. High pH of the inter-mixed blends of CS and PVOH resulted in higher viscosity, but weaker intermolecular associations as depicted by the rapidly declining viscosity. These findings demonstrated the potentials of PEF in the microstructural modification of macromolecular systems.

Keywords: PEF; pulsed electric fields; modification; intermolecular interaction.

DOI: 10.1504/IJNT.2018.098430

International Journal of Nanotechnology, 2018 Vol.15 No.8/9/10, pp.655 - 662

Published online: 22 Mar 2019 *

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